JP2020118468A - Corrosion resistance test device of coated metal material - Google Patents

Abstract

To provide a corrosion resistance test device capable of improving reliability of a corrosion resistance test with a simple configuration.SOLUTION: A corrosion resistance test device of a coated metal material in which a surface treatment film is provided in a metal base material comprises: a container mounted on the surface treatment film and including a plurality of hydrous electrolyte material holding parts which open in a bottom surface in contact with the surface treatment film; a hydrous electrolyte material housed in each of the hydrous electrolyte material holding parts of the container and coming into contact with each of a plurality of mutually separate measurement portions of the surface treatment film; a plurality of electrodes coming into contact with the hydrous electrolyte material housed in each of the hydrous electrolyte material holding parts; an external circuit connecting between the plurality of electrodes; and conducting means for conducting to the metal base material via the electrodes and the external circuit.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a corrosion resistance test apparatus for coated metal materials.

Conventionally, a corrosion acceleration test such as a combined cycle test and a salt spray test has been performed as a method for evaluating coating film performance.

However, in such a corrosion acceleration test, several months are required for the evaluation, and therefore, for example, it is possible to easily evaluate the film quality of the coating material with different constituent materials and baking conditions of the coated steel sheet, and to quickly optimize the coating conditions. Have difficulty. Therefore, it is desired to establish a quantitative evaluation method for quickly and simply evaluating the corrosion resistance of a coated steel sheet in the field of material development, process control in a coating plant, and quality control related to vehicle rust prevention.

On the other hand, in Patent Document 1, as a method for evaluating the corrosion resistance of the film applied to the surface of the metal member, the metal member and the counter electrode member are immersed in water or an electrolyte solution, and the negative terminal side of the measurement power source is made of metal. It is described that the positive terminal side of the member is electrically connected to a counter electrode member, and the anticorrosion performance of the film is evaluated based on the oxygen diffusion limit current flowing from the counter electrode member through the film to the metal member.

In Patent Document 2, an electrode is arranged on the coating film surface side of a coated metal material via a hydrous electrolyte material, and a voltage is applied between the base material of the coated metal material and the coating film surface to cause dielectric breakdown of the coating film. It is described that the corrosion resistance of the coated metal material is evaluated based on the voltage value at the time of performing.

In Patent Document 3, an electrode is arranged on the coating film surface side of a coated metal material via a hydrous electrolyte material, the hydrous electrolyte material is permeated into the coating film of the coated metal material, and the base material of the coated metal material and the coating film surface. It is described that a voltage is applied between and, and the corrosion resistance of the coated metal material is evaluated based on the value related to the current flowing with the application of the voltage.

JP, 2007-271501, A JP, 2016-50915, A JP, 2016-50916, A

By the way, a plurality of measurement portions are provided on the surface-treated film of the coated metal material, a plurality of electrodes and an electrolyte material are arranged so as to correspond to each of the plurality of measurement portions, and an electric current is applied between the plurality of electrodes to coat the electrodes. It is conceivable to test the corrosion resistance of metal materials. In this case, since the electrodes and the electrolyte material are arranged at the positions corresponding to the plurality of measurement parts, if a plurality of measurement containers are arranged, problems such as the configuration of the corrosion resistance test device becoming complicated, and the displacement of the plurality of measurement containers will occur. However, there was a problem such as a decrease in reliability of the corrosion resistance test due to the above.

Therefore, it is an object of the present disclosure to provide a corrosion resistance test apparatus that has a simple structure and can improve the reliability of the corrosion resistance test.

In order to solve the above problems, the corrosion resistance test apparatus disclosed herein is a corrosion resistance test apparatus for a coated metal material in which a surface treatment film is provided on a metal base material, and is placed on the surface treatment film. A container provided with a plurality of water-containing electrolyte material holding portions that open at the bottom surface in contact with the surface-treated membrane, and each of the water-containing electrolyte material holding portions of the container are housed in a plurality of separated measurement portions of the surface-treated membrane. Water-containing electrolyte material in contact with each, a plurality of electrodes in contact with the water-containing electrolyte material accommodated in each of the water-containing electrolyte material holding portion, an external circuit connecting between the plurality of electrodes, the electrode and the external circuit And an energizing means for energizing the metal base material via the.

According to this configuration, by placing a container having a plurality of water-containing electrolyte material holding portions that contain the water-containing electrolyte material on the surface treatment membrane, with a simple configuration, each of the water-containing electrolyte material of the plurality of measurement portions. Can be placed in contact with. Further, since the plurality of water-containing electrolyte material holding portions are provided in one container, it is easy to arrange the water-containing electrolyte material so as to come into contact with a predetermined measurement portion, and the position of the water-containing electrolyte material is arranged. The deviation is unlikely to occur, and the reliability of the corrosion resistance test can be improved. Then, a stable corrosion resistance test can be performed in a shorter time.

In a preferred embodiment, the bottom surface of the container is flat, and each of the water-containing electrolyte material holding portions is provided with an opening provided in the bottom surface, and comprises a through hole penetrating the container in a direction perpendicular to the bottom surface. It may be configured.

According to this configuration, since the through hole provided in the container functions as the water-containing electrolyte material holding portion, it is possible to perform a highly reliable corrosion resistance test with a simpler configuration.

The metal base material is, for example, a steel material that constitutes home appliances, building materials, automobile parts, etc., for example, a cold rolled steel plate (SPC), a galvannealed steel plate (GA), a high tensile steel plate or a hot stamp material. Etc., or may be a light alloy material. The metal base material may have a chemical conversion coating (phosphate coating (for example, zinc phosphate coating), chromate coating, etc.) formed on the surface thereof.

Particularly preferably, the metal base material may be a steel plate, and the container may be configured to include a magnet arranged on the bottom surface side and near each opening of the through hole. ..

According to this configuration, since the magnet is arranged on the bottom surface side of the container, the container is attracted and fixed by the magnetic force to the coated metal material using the steel plate as the metal base material. Thus, the displacement of the container can be effectively suppressed, and the reliability of the corrosion resistance test can be improved. As the magnet, it is desirable to use, for example, a neodymium magnet, a samarium cobalt magnet, or the like from the viewpoint of obtaining a high attractive force.

Further, preferably, the first heating element arranged on the outer peripheral portion of the container is connected to the first heating element so as to cover the outer periphery of the water-containing electrolyte material holding portion, and the temperature of the first heating element is adjusted. It may be configured to include a temperature controller for controlling.

According to this configuration, the temperature of the water-containing electrolyte material accommodated in the water-containing electrolyte material holding portion can be adjusted by the first heating element and the temperature controller, so that the temperature of the water-containing electrolyte material is kept constant over a desired test time. Can be kept at By doing so, the corrosion resistance test under various temperature conditions can be performed accurately. A rubber heater, a film heater, or the like can be used as the first heating element.

A second heating element arranged on the opposite side of the coated metal material from the side on which the container is arranged is provided, and the temperature of the first heating element and the second heating element is 30° C. or higher and 100° C. by the temperature controller. According to the present technology that is controlled below, it is possible to perform a highly reliable corrosion resistance test under a predetermined temperature condition by keeping the hydrous electrolyte material and the coating metal material at the above temperature by the first heating element and the second heating element. Become. A hot plate or the like can be used as the second heating element.

Further, it is preferable that the container includes a bottom portion made of a silicone resin that forms a bottom surface of the container, and a main body made of an insulating resin material and extending on a side of the bottom portion opposite to the bottom surface.

According to the present technology, the bottom surface of the container that comes into contact with the surface-treated film is made of a silicone resin, so that the adhesion between the container and the surface-treated film can be improved, and the contact between the container and the surface-treated film can be improved. Leakage of the hydrous electrolyte material can be effectively suppressed. Further, by making the container body made of an insulating resin material, it is possible to reduce the weight and cost of the container while ensuring the insulation between the water-containing electrolyte material holding portions, and thus the weight of the device. And cost reduction.

In a preferred embodiment, each of the measurement portions includes an artificial scratch that penetrates the surface-treated film and reaches the metal base material, and at least one of the artificial scratches serves as an anode site by the current-carrying means. It is possible to adopt a configuration in which the metal base material is energized so that at least one of the above becomes a cathode site and the corrosion of the coated metal material proceeds.

Corrosion of metals is anodic reaction (oxidation reaction) in which a metal in contact with water dissolves (ionizes) to generate free electrons, and cathodic reaction (reduction reaction) in which dissolved oxygen in water forms hydroxyl group OH ^{− due} to the free electrons. It is known that progress occurs when the two occur at the same time.

In the present technology, at least one of the plurality of artificial scratches on the coated metal material serves as an anode site that causes a metal elution reaction (oxidation reaction) of the metal base material. At least one other artificial flaw in which the electrons generated at the anode site flow through the metallic substrate becomes the cathode site where the reduction reaction by the electrons occurs.

At the anode site, the eluted metal ions are attracted to the electrode (negative electrode) and react with dissolved oxygen in the water-containing electrolyte material and OH ⁻ generated by electrolysis of water at the electrode (negative electrode) to form iron hydroxide. .. Since electrons are supplied to this anode site, the metal of the metal base material becomes ions and dissolves in the water-containing electrolyte material to some extent by the same principle as in the case of cathodic protection, but the corrosion of the coated metal material does not proceed.

On the other hand, at the cathode site, electrons flowing from the anode site through the metal base material react with water and dissolved oxygen that have permeated the surface-treated film, and ionized H ⁺ in water to generate hydrogen and OH ⁻ . Also, hydrogen is generated by electrolysis of water. As a result, the pH under the surface-treated film increases, and the corrosion of the coated metal material proceeds.

Since the generation of OH ^{− at} the cathode site corresponds to the cathodic reaction of the corrosion model described above, the corrosion resistance test using the device according to the present technology is performed by applying an electric current to the metal base material by an external circuit to remove the coated metal material. It can be said that it is an accelerated reproduction of actual corrosion.

Then, the artificial scratch that becomes the cathode site becomes alkaline (generation of OH ⁻ ), so that the base treatment (chemical conversion treatment) on the surface of the metal base material is damaged, and the adhesion of the surface treatment film deteriorates ( If the base treatment is not performed, the adhesion between the metal base material and the surface treatment film is simply reduced), and the surface treatment film swells. Further, hydrogen gas generated by electrolysis of water or reduction of H ⁺ promotes swelling of the surface-treated film. Therefore, by observing the degree of swelling of the surface-treated film, the corrosion progress rate of the test material in the corrosion resistance test can be measured.

As described above, in the present technology, the anode site and the cathode site are artificially formed on the coated metal material, and the container is used to hold the water-containing electrolyte material so as to come into contact with each of the artificial scratches, while using the energizing means. By energizing, the corrosion of artificial scratches is promoted. Then, since the actual corrosion is reproduced in an accelerated manner, the obtained corrosion progress rate data has a high correlation with the actual corrosion progress rate. Therefore, according to the present technology, it is possible to perform a highly reliable test on the corrosion resistance of the coated metal material.

The distance between the plurality of artificial scratches is preferably 2 cm or more, and more preferably 3 cm or more from the viewpoint of easy confirmation of the swelling of the surface-treated film on the cathode site.

The diameter of the artificial scratch on the cathode site is preferably 0.1 mm or more and 5 mm or less.

Regarding the diameter of the artificial scratch on the cathode site (exposed diameter of the metal base material), the smaller the diameter, the lower the electrical conductivity and the more difficult the cathode reaction proceeds. On the other hand, when the diameter becomes large, the cathodic reaction becomes unstable, and the accelerated reproducibility of corrosion deteriorates. By setting the diameter of the artificial scratch within the above range, both acceleration of the cathode reaction and accelerated reproducibility of corrosion can be achieved.

It is desirable that the energization by the energizing means has a current value of 10 μA or more and 10 mA or less.

With respect to the current value for energization, the smaller the current value is, the less accelerated the corrosion is, and the longer the test becomes. On the other hand, when the current value becomes large, the corrosion reaction rate becomes unstable, and the correlation with the actual progress of corrosion deteriorates. By setting the current value within the above range, it is possible to reduce the test time and improve the reliability of the test.

The water-containing electrolyte material is preferably a muddy material containing water, a supporting electrolyte and a clay mineral.

The clay mineral promotes the migration of ions and the penetration of water into the surface-treated film, and can effectively promote the progress of corrosion.

The clay mineral is preferably layered silicate mineral or zeolite. The layered silicate mineral is preferably at least one selected from kaolinite, montmorillonite, sericite, illite, glowconite, chlorite and talc.

The supporting electrolyte is preferably at least one salt selected from sodium chloride, sodium sulfate and calcium chloride.

The surface treatment film is preferably a resin coating film.

Examples of the resin coating film include cationic electrodeposition coating film (undercoating coating film) of epoxy resin type, acrylic resin type, etc., laminated coating film in which an overcoating coating film is superposed on the electrodeposition coating film, electrodeposition coating film It may be a laminated coating film in which an intermediate coating film and a top coating film are superposed on each other.

The electrodes may be embedded in the hydrous electrolyte material in order to energize the metal base material. As such an electrode, a carbon electrode, a platinum electrode or the like can be used, and in particular, a perforated electrode having at least one hole facing the surface-treated film can be adopted. It is preferable to dispose it substantially parallel to the surface treatment film. For example, the perforated electrode has a ring shape having a hole in the center, and the hole is provided so as to face the artificial wound. Alternatively, a mesh-shaped electrode may be adopted as the perforated electrode, and the mesh electrode may be arranged so as to be substantially parallel to the surface-treated film in a state of being buried in the hydrous electrolyte material.

According to the present disclosure, by placing a container having a plurality of water-containing electrolyte material holding portions that contain the water-containing electrolyte material on the surface treatment membrane, with a simple configuration, each of the water-containing electrolyte material of the plurality of measurement portions. Can be placed in contact with. Further, since the plurality of water-containing electrolyte material holding portions are provided in one container, it is easy to arrange the water-containing electrolyte material so as to come into contact with a predetermined measurement portion, and the position of the water-containing electrolyte material is arranged. The deviation is unlikely to occur, and the reliability of the corrosion resistance test can be improved. Then, a stable corrosion resistance test can be performed in a shorter time.

The figure which shows the corrosion resistance test apparatus which concerns on 1st Embodiment. Sectional drawing in the AA line of FIG. The figure which shows the principle of the corrosion resistance test using the corrosion resistance test apparatus of FIG. The top view, front view, and bottom view of the main body of the container. The chart which shows the corrosion resistance test result of the sample material 1 of the comparative example 3. 5 is a graph showing the correlation between the corrosion progress rate of Reference Example 1 and the corrosion progress rate of Test Example 1. Deposits of water on the coated film, 5% NaCl (spray), and water absorption and swelling table showing the incidence of the coating film when a 5% CaCl ₂ sprays. The figure which shows the water absorption amount of a coating film and the swelling generation rate when the deposit on a coating film is a simulation mud. The figure which shows the water absorption amount and swelling generation rate of a coating film when the deposit on a coating film is 5% NaCl (immersion). The graph which shows the infiltration rate of the water in a coating film in the deposit on various coating films. The current plot figure at the time of constant current energization control in a corrosion resistance test. The current plot figure at the time of constant voltage electricity control in a corrosion resistance test. The perspective view of the cover used for the corrosion resistance testing apparatus which concerns on 2nd Embodiment.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The description of the preferred embodiments below is merely exemplary in nature and is not intended to limit the present invention, its application, or its application.

(First embodiment)
<Corrosion resistance tester>
As shown in FIGS. 1 to 3, the corrosion resistance test apparatus 100 according to the present embodiment is an apparatus for testing the corrosion resistance of the coated metal material 1, and includes a container 30, a water-containing electrolyte material 6, an electrode 12, and The external circuit 7, the energizing means 8, the rubber heater 34 (first heating element), the hot plate 35 (second heating element), and the temperature controller 36 are provided.

<Coated metal material>
As shown in FIGS. 2 and 3, the coated metal material 1 is a resin coating film as a surface treatment film on a steel plate 2 having a chemical conversion film 3 formed on the surface as a metal base material, that is, the present embodiment. In, the electrodeposition coating film 4 is provided.

As shown in FIG. 2 and FIG. 3, in the coated metal material 1, the electrodeposition coating film 4 and the chemical conversion coating 4 are formed at two places (plurality) apart from each other in a form included in the measurement portion 4A in which the hydrous electrolyte material 6 is arranged. An artificial scratch 5 that penetrates the film 3 and reaches the steel plate 2 is added. The diameter of the exposed portion of the steel plate 2 due to the artificial scratch 5 (hereinafter, may be referred to as "the diameter of the artificial scratch 5") is determined by the migration of ions and the penetration of water into the electrodeposition coating film 4 in the corrosion resistance test described later. From the viewpoint of effectively promoting corrosion in the artificial scratch 5, and preferably 0.1 mm or more and 5 mm or less (the area of the exposed surface is 0.01 mm ² or more and 25 mm ² or less), and more preferably 0.3 mm or more and 2 mm. It is particularly preferable that the length is 0.5 mm or more and 1.5 mm or less. Further, the distance between the two artificial scratches 5 is preferably 2 cm or more from the viewpoint of easy confirmation of swelling of the electrodeposition coating film 4 on the cathode site in the corrosion resistance evaluation step of the corrosion resistance test method described later. It is more preferably 3 cm or more.

<Container>
As shown in FIGS. 1 and 2, the container 30 is placed on the electrodeposition coating film 4 of the coated metal material 1. The container 30 has a flat bottom surface 32A, and includes a bottom portion 32 that forms the bottom surface 32A, and an insulative main body 31 that extends on the opposite side of the bottom portion 32 from the bottom surface 32A.

As shown in FIGS. 1 and 4, the container 30 is a member having an oval shape in a plan view, and two (a plurality of) containers 30 penetrating the container 30, that is, the main body 31 and the bottom portion 32 of the container 30 in a direction substantially perpendicular to the bottom surface 32A. ) Is a cylindrical member having a through hole 11. The through hole 11 has an opening 11A provided on the bottom surface 32A. The water-containing electrolyte material 6 is accommodated in the through hole 11, and the water-containing electrolyte material 6 is in contact with the surface of the electrodeposition coating film 4. That is, the two through holes 11 form a water-containing electrolyte material holding portion that opens at the bottom surface 32</b>A in contact with the electrodeposition coating film 4. Then, in the state where the container 30 is placed on the electrodeposition coating film 4 of the coated metal material 1, the region of the coated metal material 1 defined by the opening 11A becomes the measurement portion 4A.

The bottom portion 32 is, for example, a sheet-like sealing material made of silicone resin, and is for improving the adhesion between the container 30 and the electrodeposition coating film 4 when the container 30 is placed on the coated metal material 1. Is. Thus, leakage of the hydrous electrolyte material 6 between the container 30 and the electrodeposition coating film 4 can be effectively suppressed.

As shown in FIG. 4, the main body 31 of the container 30 includes a pedestal portion 302 on the bottom portion 32 side and an extension portion 301 extending on the pedestal portion 302 on the side opposite to the bottom portion 32. The pedestal portion 302 has a larger diameter than the extension portion 301 in plan view, and a step portion 303 is provided at a transition portion from the pedestal portion 302 to the extension portion 301. A groove 304 is formed on the bottom portion 32 side of the pedestal portion 302. The groove 304 is arranged around the through hole 11 in the vicinity of each opening 11A of the through hole 11, and the ring-shaped magnet 33 is housed in the groove 304. Thereby, when the container 30 is placed on the electrodeposition coating film 4 of the coated metal material 1, the container 30 is attracted and fixed to the coated metal material 1 by the attraction force of the magnet 33. Thus, the displacement of the container 30 can be effectively suppressed, and the reliability of the corrosion resistance test described later can be improved. It should be noted that the magnet 33 is preferably sealed with, for example, epoxy resin after being housed in the groove 304. This can prevent the magnet 33 from falling out of the groove 304, leakage of the hydrous electrolyte material 6 from the through hole 11 to the groove 304, and the like.

Further, the main body 31 of the container 30 can be made of a resin material such as an acrylic resin or an epoxy resin or a ceramic material from the viewpoint of ensuring insulation between the two through holes 11. From the viewpoint of reducing the weight and cost of the container 30, it is particularly preferable to use a resin material such as acrylic resin or epoxy resin.

The diameter of the through hole 11 is preferably larger than the diameter of the artificial scratch 5. The container 30 is preferably placed on the electrodeposition coating film 4 so that the through hole 11 is concentric with the artificial scratch 5. With this structure, it is possible to cover the entire artificial scratch 5 with the hydrous electrolyte material 6 and accommodate a sufficient amount of the hydrous electrolyte material 6 for the corrosion resistance test. As described above, when the diameter of the artificial scratch 5 is 0.1 mm or more and 5 mm or less, the diameter of the through hole 11 can be, for example, 0.5 mm or more and 40 mm or less, preferably 0.5 mm or more and 35 mm or less. .. With this configuration, it is possible to cover the entire artificial scratch 5 with the hydrous electrolyte material 6 and accommodate a sufficient amount of the hydrous electrolyte material 6 for the corrosion resistance test.

<Hydrolyte material>
The water-containing electrolyte material 6 is housed in each of the through holes 11 of the container 30. Then, it is in contact with each of the two measurement portions 4A of the electrodeposition coating film 4 which are separated from each other, and penetrates into the artificial wound 5 provided in the measurement portion 4A.

The water-containing electrolyte material 6 is, for example, a muddy material containing water, a supporting electrolyte, and preferably clay mineral, and functions as a conductive material.

As the supporting electrolyte (salt), for example, at least one salt selected from sodium chloride, sodium sulfate, calcium chloride, calcium phosphate, potassium chloride, potassium nitrate, potassium hydrogen tartrate and magnesium sulfate can be adopted, and particularly preferably At least one salt selected from sodium chloride, sodium sulfate and calcium chloride can be employed. The content of the supporting electrolyte in the hydrous electrolyte material 6 is preferably 1% by mass or more and 20% by mass or less, more preferably 3% by mass or more and 15% by mass or less, and particularly preferably 5% by mass or more and 10% by mass or less. is there.

The clay mineral serves to make the water-containing electrolyte material 6 into a mud shape, promote the movement of ions into the electrodeposition coating film 4 and the penetration of water, and promote the progress of corrosion. As the clay mineral, for example, layered silicate mineral or zeolite can be adopted. As the layered silicate mineral, for example, at least one selected from kaolinite, montmorillonite, sericite, illite, glowconite, chlorite, and talc can be adopted, and kaolinite is particularly preferably adopted. be able to. The content of the clay mineral in the hydrous electrolyte material 6 is preferably 1% by mass or more and 70% by mass or less, more preferably 10% by mass or more and 50% by mass or less, and particularly preferably 20% by mass or more and 30% by mass or less.

The hydrous electrolyte material 6 may contain additives other than water, a supporting electrolyte and a clay mineral. Specific examples of such additives include organic solvents such as acetone, ethanol, toluene, and methanol. When the water-containing electrolyte material 6 contains an organic solvent, the content of the organic solvent is preferably 5% or more and 60% or less with respect to water. More preferably, the volume ratio is 10% or more and 40% or less, and 20% or more and 30% or less.

<Electrode, external circuit and energizing means>
The electrodes 12 are provided at both ends of the external circuit 7. The water-containing electrolyte material 6 in the through hole 11 is embedded in the water-containing electrolyte material 6 and is in contact with the water-containing electrolyte material 6.

The electrode 12 is a ring-shaped perforated electrode having a hole 12a in the center, and is arranged in parallel with the electrodeposition coating film 4 so that the hole 12a faces the artificial scratch 5 and is concentric with the artificial scratch 5. ing. As a result, the electrode 12 is arranged so as to surround the artificial scratch 5, so that the voltage is stably applied to the electrodeposition coating 4 around the artificial scratch 5, and the ions on the electrodeposition coating 4 are energized when energized. Efficient movement and water penetration. Further, since hydrogen gas generated in the artificial scratch 5 escapes through the hole 12a of the electrode 12, it is possible to avoid hydrogen gas from staying between the electrode 12 and the electrodeposition coating film 4, that is, the electrical conductivity deteriorates. Can be avoided.

The external circuit 7 is a wiring that connects the two electrodes 12, and electrically connects the two measurement portions 4A of the coated metal material 1 via the hydrous electrolyte material 6 and the electrodes 12.

The energizing means 8 is composed of a DC constant current source for energizing the steel sheet 2 via the external circuit 7, the electrode 12 and the hydrous electrolyte material 6. As the energizing means 8, for example, a galvanostat can be adopted. Then, in the corrosion resistance test described below, the current value is controlled to preferably 10 μA or more and 10 mA or less, more preferably 100 μA or more and 5 mA or less, and particularly preferably 500 μA or more and 2 mA or less from the viewpoint of promoting corrosion in the artificial scratch 5.

<Rubber heater, hot plate and temperature controller>
The rubber heater 34 is arranged on the outer peripheral portion of the container 30 so as to cover the outer periphery of the through hole 11, and is for heating and adjusting the temperature of the water-containing electrolyte material 6 in the through hole 11. Specifically, as shown in FIGS. 1 and 4, the rubber heater 34 is arranged on the step portion 303 of the pedestal portion 302 of the main body 31 of the container 30 so as to cover the outer peripheral surface 301A of the extension portion 301. It The rubber heater 34 is adhesively fixed to the outer peripheral surface 301A using, for example, an adhesive tape or the like.

The hot plate 35 is disposed on the side of the coated metal material 1 opposite to the side where the container 30 is disposed, that is, on the steel plate 2 side, and is for heating and adjusting the temperature of the coated metal material 1 from the back side.

The temperature controller 36 is electrically connected to the rubber heater 34 and the hot plate 35, and controls the temperatures of the rubber heater 34 and the hot plate 35. Thus, the coating metal material 1 and the water-containing electrolyte material 6 can be heated or adjusted in temperature.

According to this configuration, since the water-containing electrolyte material 6 and the coating metal material 1 can be appropriately heated, in the corrosion resistance test described below, the migration of ions to the electrodeposition coating film 4 and the penetration of water are promoted, Corrosion in the artificial scratch 5 is effectively progressed, and a corrosion resistance test having a shorter period and higher reliability can be performed. Moreover, since the temperature of the hydrous electrolyte material 6 and the coating metal material 1 can be kept constant over a desired test time, the corrosion resistance test under various temperature conditions can be performed accurately.

It should be noted that both the heating and temperature adjustment of the coated metal material 1 and the water-containing electrolyte material 6 may be performed both, or only one of them may be performed. From the viewpoint of making the temperature distributions of the coated metal material 1 and the hydrous electrolyte material 6 uniform, it is desirable to perform heating and temperature adjustment for both. Specifically, by controlling the temperature of the rubber heater 34 and/or the hot plate 35 with the temperature controller 36, the temperature of the coated metal material 1 and/or the water-containing electrolyte material 6 is preferably 30° C. or higher and 100° C. or lower, It is preferably 50° C. or higher and 100° C. or lower, and particularly preferably 50° C. or higher and 80° C. or lower.

<Corrosion resistance test method>
An example of the corrosion resistance test method for the coated metal material 1 using the corrosion resistance test apparatus 100 will be described in the order of steps.

-Step of adding artificial scratch-
Artificial scratches 5 that penetrate the electrodeposition coating film 4 and the chemical conversion coating 3 and reach the steel plate 2 are added to two positions apart from each other on the coated metal material 1. The type of tool for attaching the artificial scratch 5 is not particularly limited. In order to prevent variations in the size and depth of the artificial scratch 5, that is, to make a quantitative scratch, it is preferable to use, for example, a Vickers hardness tester and to make a scratch with a predetermined load using the indenter.

-Processing step-
A container 30 is erected on the electrodeposition coating film 4 of the coated metal material 1 so that the through holes 11 surround each of the two artificial scratches 5, and a predetermined amount of the mud-containing water-containing electrolyte material 6 is placed in the through holes 11. Put in. At this time, the ring-shaped electrodes 12 provided at both ends of the external circuit 7 are set to be embedded in the hydrous electrolyte material 6. The through hole 11 is preferably provided concentrically with the artificial scratch 5. Further, it is preferable that the electrode 12 is provided so that the hole 12a portion is parallel to the surface of the electrodeposition coating film 4 and is concentric with the artificial scratch 5.

As described above, the water-containing electrolyte material 6 contained in the through hole 11 comes into contact with the surface of the electrodeposition coating film 4 and enters the artificial scratch 5. Then, the artificial scratches 5 at the two locations are electrically connected to each other by the external circuit 7 through the hydrous electrolyte material 6 and the electrode 12 that are in contact with the artificial scratches 5.

-Holding step-
Before the next energization step, the hydrous electrolyte material 6 is housed in the through holes 11 and arranged on the surface of the electrodeposition coating film 4, preferably for 1 minute or more and 1 day or less, more preferably 10 minutes or more 120 It is desirable to allow the hydrous electrolyte material 6 to penetrate into the electrodeposition coating film 4 by holding it for 5 minutes or less, particularly preferably for 15 minutes or more and 60 minutes or less.

Generally, in a coated metal material provided with a coating film, a corrosion factor such as salt water penetrates into the coating film and reaches the base material to start corrosion. Therefore, the corrosion process of the coated metal material is divided into the process until the corrosion occurs and the process where the corrosion progresses, and the period until the corrosion starts (corrosion inhibition period) and the rate at which the corrosion progresses (corrosion progress It can be evaluated by determining

By providing the holding step before the energization step, the migration of ions into the electrodeposition coating film 4 and the permeation of water, especially the ions in the electrodeposition coating film 4 around the artificial scratch 5 as shown by the dot pattern in FIG. Movement and water penetration can be promoted in advance. Then, in the vicinity of the electrode 12 of the coated metal material 1, a state after the end of the corrosion suppression period can be artificially created. Then, the corrosion of the chemical conversion coating 3 and the steel sheet 2 in the next energization step can be more smoothly progressed, and the progress of coating swelling of the electrodeposition coating 4 showing the corrosion progress rate can be promoted, and the test time can be shortened. Can be promoted. In addition, since the power is supplied in a state where the corrosion suppression period ends, so to speak, the rate of corrosion progress can be measured accurately, and the reliability of the corrosion resistance test can be improved.

In the holding step and the next energization step, it is desirable to use the temperature controller 36 to adjust and hold the temperatures of the rubber heater 34 and the hot plate 35 within the above temperature range. As a result, the migration of ions to the electrodeposition coating film 4 and the penetration of water are promoted, the corrosion in the artificial scratches 5 is effectively advanced, and a corrosion resistance test with a shorter period and higher reliability becomes possible.

-Energization step-
The energizing means 8 is operated to energize the steel plate 2 of the coated metal material 1 through the electrode 12, the water-containing electrolyte material 6 and the electrodeposition coating film 4 by the external circuit 7. This energization is preferably controlled by constant current so that the current value is a constant current value within the above range.

By the energization, one of the two artificial scratches 5 connected to the negative electrode side of the energizing means 8 (on the left side in FIG. 3), the electron e ⁻ flows from the hydrous electrolyte material 6 into the steel plate 2. Then, this one artificial scratch 5 becomes an anode site.

The e ⁻ flowing into the steel plate 2 moves to the other artificial scratch 5 (on the right side in FIG. 3) through the steel plate 2 and is released to the hydrous electrolyte material 6 at the other artificial scratch 5. Then, the other artificial scratch 5 becomes a cathode site.

At the anode site, since e ⁻ is supplied, Fe of the steel plate 2 becomes ions and dissolves in the water-containing electrolyte material 6 (Fe → Fe ²⁺ +2e ⁻ ) according to the same principle as that of the electrocorrosion. Corrosion does not progress.

On the other hand, at the cathode site, since electrons move from the anode site, OH ⁻ is generated by the reaction of water in the water-containing electrolyte material 6, dissolved oxygen and the electron e ⁻ (H ₂ O+1/2O ₂ +2e ^−). → 2OH ⁻ ). Further, hydrogen is generated by the reaction between the ionized hydrogen ions of the water-containing electrolyte material 6 and the electron e ⁻ (2H ⁺ +2e ⁻ →H ₂ ). The production of OH ⁻ and hydrogen is a cathode reaction (reduction reaction). Also, hydrogen is generated by electrolysis of water.

Then, at the cathode site, alkalinization proceeds with the generation of OH ⁻ , so that the chemical conversion film 3 dissolves and corrosion of the steel sheet 2 proceeds (generation of hydrated iron oxide). Then, the adhesion of the electrodeposition coating film 4 to the steel plate 2 is reduced. The generation of hydrogen gas causes the electrodeposition coating film 4 to swell, and the corrosion of the steel plate 2 progresses from the site of the artificial scratch 5 to the surroundings. As described above, since the swelling of the electrodeposition coating film 4 progresses with the progress of the cathode reaction at the cathode site, the degree of swelling of the electrodeposition coating film 4 at this cathode site should be evaluated in the corrosion resistance evaluation step described later. Thus, the corrosion resistance of the coated metal material 1 can be evaluated.

The energizing time in the energizing step may be, for example, 0.5 hours or more and 24 hours or less from the viewpoint of obtaining a sufficient spread of the coating film swell. The energization time is preferably 1 hour or more and 10 hours or less, more preferably 1 hour or more and 5 hours or less.

Further, in the energization by the external circuit 7, a voltage is applied to the hydrous electrolyte material 6 at the cathode site, so that cations (Na ⁺ etc.) in the hydrous electrolyte material 6 pass through the electrodeposition coating film 4 and reach the steel sheet 2. Move towards. Then, the water is attracted to the cations and permeates the electrodeposition coating film 4. On the other hand, also at the anode site, anions (Cl ⁻ or the like) of the water-containing electrolyte material 6 move toward the steel plate 2 through the electrodeposition coating film 4 and are dragged by this, and water permeates into the electrodeposition coating film 4. I will do it.

Thus, at the anode site and the cathode site, the above-mentioned energization promotes the penetration of ions and water into the electrodeposition coating film 4 around the artificial scratch 5, so that the flow of electricity quickly becomes stable. Therefore, the progress of corrosion from the artificial scratch 5 at the cathode site to its surroundings becomes stable.

-Corrosion resistance evaluation step-
As described above, the development of corrosion at the cathode site appears as the development of swelling of the electrodeposition coating film 4, that is, the expansion of the coating film swelling range. Therefore, the corrosion resistance of the coated metal material 1, in particular, the rate of corrosion progress can be evaluated by observing the extent of swelling of the coating film after a predetermined time has elapsed from the start of energization.

In addition, the extent of spread of the coating film swell can be determined by applying an adhesive tape to the electrodeposition coating film 4 after the corrosion resistance test, peeling off the swelled portion of the electrodeposition coating film 4, and exposing the exposed surface of the steel plate 2 (hereinafter, referred to as It can be known by measuring the "peeling diameter").

Specifically, FIG. 5 shows appearance photographs of the anode site and the cathode site of the sample material 1 of Comparative Example 3 in the corrosion resistance test described later. The appearance photograph (before peeling) is a photograph of the surface of the coated metal material 1 after the test, and the appearance photograph (after peeling) is the electrodeposition coating film 4 swelled from the surface of the coated metal material 1 after the test. 2 is a photograph after peeling with a pressure-sensitive adhesive tape. At the anode site, formation of the artificial scratch 5 can be confirmed, but swelling of the electrodeposition coating film 4 cannot be observed. On the other hand, at the cathode site, the artificial scratch 5 and the swelling of the electrodeposition coating film 4 formed around the artificial scratch 5 are observed.

When the corrosion resistance of the coated metal material 1 is evaluated in association with the actual corrosion test (salt spray test), the corrosion progress rate (expansion amount of coating film swelling diameter per unit time) by the corrosion resistance test and the actual corrosion test The relationship with the corrosion progress rate is obtained in advance, and based on the result of the corrosion resistance test, it is possible to see how much the corrosion resistance corresponds to in the actual corrosion test.

<Experimental example>
-Corrosion resistance test-
As the test materials (coated metal materials), seven kinds shown in Table 1 were prepared, which differed in coating conditions, that is, chemical conversion treatment time with zinc phosphate and baking conditions for electrodeposition coating. In each of the test materials 1 to 7, the metal base material is the steel plate 2, and the thickness of the electrodeposition coating film 4 is 10 μm. The details of the coating conditions A to G shown in Table 1 are shown in Table 2.

A corrosion resistance test was performed on each of the test materials by using the corrosion resistance test apparatus of the embodiment shown in FIGS. The main body 31 of the container 30 is made of acrylic resin, and the dimensions of the main body 31 are set according to the distance between the artificial scratches 5 and the size of the electrode 12 described below. As the magnet 33, a ring-type neodymium magnet having a thickness of 3 mm and a height of 7 mm was used. The magnet 33 was housed in the groove 304 and then sealed with epoxy resin. Then, as shown in FIGS. 1 and 2, the bottom portion 32 made of silicone resin is provided so as to cover the groove portion 304 in which the magnet 33 is accommodated.

The test material was applied quantitatively using a Vickers hardness tester, that is, artificial scratches 5 with a diameter of 1 mm that reach the steel plate with a load (testing force) of 30 kg were applied at two locations at intervals of 4 cm.

In the tests of Comparative Examples 1 and 2, as the water-containing electrolyte material 6, an aqueous sodium chloride solution prepared by mixing 50 g of sodium chloride as a supporting electrolyte with 1.3 L of water was used. In addition, in the tests of Comparative Examples 3 and 4 and Reference Example 1, as a water-containing electrolyte material 6, 1.3 L of water was mixed with 50 g of sodium chloride as a supporting electrolyte and 500 g of kaolinite as a clay mineral. I used mud.

As the electrode 12, a ring-shaped perforated electrode (made of platinum) having an outer diameter of about 32 mm and an inner diameter of about 30 mm was used.

A hot plate was arranged below the steel plate, and a rubber heater was wound around the through hole to heat and maintain the temperature of the steel plate and the water-containing electrolyte material 6 at the temperatures shown in Table 1.

The current value of the energizing means 8 was set to 1 mA, and energization was performed during the energizing time shown in Table 1. In addition, in Comparative Examples 1 to 4, energization was performed immediately after the processing step. In Reference Example 1, after the treatment step and before the energization step, the sample was held at 70° C. for 30 minutes.

After the completion of energization, the corrosion progress rate (progression rate of swelling of the coating film) of each test material was measured by the method described in the above corrosion resistance evaluation step.

Table 1 shows the corrosion progress rate (the swelling rate of the coating film) obtained by the tests of Reference Example 1 and Comparative Examples 1 to 4. Further, as Test Example 1, the corrosion progress rate obtained as a result of the actual corrosion test in which simulated mud is adhered to the artificial scratches 5 of each test material and exposed to an environment of a temperature of 50° C. and a humidity of 98% is shown. Further, FIG. 6 shows the correlation between the corrosion progress rate of Reference Example 1 and the corrosion progress rate of Test Example 1.

As shown in Table 1 and FIG. 6, for the test materials 1 to 5 and 7 of Reference Example 1, the correlation between the corrosion progress rate according to the present corrosion resistance test and the corrosion progress rate according to the actual corrosion test is seen. Is high (R ² =0.96).

On the other hand, as shown in Table 1, in the tests of Comparative Examples 2 and 4, the correlation with the corrosion progress rate of Test Example 1 was R ² =0.68 and 0.70, and the correlation was low. I understand. In Comparative Example 3, R ² =0.86, and although the correlation is relatively high, it can be seen that the energization time is as long as 5 hours. In the test of Comparative Example 1, no swelling of the coating film was observed in the test materials 2 to 7.

-Water absorption accelerating property of a coating film using a water-containing electrolyte material-
Various deposits were provided on the surface of various electrodeposition coating films 4 having different baking conditions or film thicknesses, and the water absorption amount of the electrodeposition coating film 4 after 9 days and the swelling occurrence rate after 9 days were examined. As shown in FIGS. 7 to 9, the types and forms of the deposits are “water”, “5% NaCl (spray)”, “5% CaCl ₂ (spray)”, “simulated mud” and “5% NaCl”. (Immersion)”. The composition of “simulated mud” is water:kaolinite:sodium chloride:sodium sulfate:calcium chloride=500:500:25:25:25 (mass ratio).

According to FIG. 7, water, 5% NaCl (spray), and 5% CaCl ₂ (spray) all had a small water absorption amount even after 9 days, and almost no swelling of the coating film was observed.

On the other hand, according to FIG. 8, in the case of the simulated mud, the water absorption amount and the swelling occurrence rate after 9 days are significantly higher than those of water, 5% NaCl (spray) and 5% CaCl ₂ (spray). Is getting bigger. In particular, comparing the case where the baking conditions of the electrodeposition coating film 4 are the same 150° C.×20 minutes, it can be seen that in the case of the simulated mud, the water absorption amount and the swelling occurrence rate are orders of magnitude higher.

According to FIG. 9, in the case of 5% NaCl (immersion), the water absorption amount and the swelling occurrence rate are larger than those of water, 5% NaCl (spray) and 5% CaCl ₂ (spray). It is considerably lower than the simulated mud of 8.

FIG. 10 is a comparison of the infiltration rates of water into the coating film in the case where the baking conditions of the electrodeposition coating film 4 are 150° C.×20 minutes for the above five types. The infiltration rate of water into the coating film is calculated from the time required for the water absorption of the coating film to reach 25 μg/mm ³ . According to the figure, in the case of the simulated mud, the penetration speed of water into the coating film is significantly higher than that in the salt water spray or the like.

-About energization control-
In the corrosion resistance test according to the present embodiment, the energization of the steel sheet 2 is not limited to the constant current control method, but may be the constant voltage control method.

Note that FIG. 11 is a current plot of energization by constant current control of 1 mA (test of the sample material 1 of Comparative Example 3), and FIG. 12 is a current plot when a constant voltage of about 1 mA of current is applied. is there. In the corrosion resistance test under constant current control and the corrosion resistance test under constant voltage control, the other test conditions except the energization conditions are the same as the test conditions for the test material 1 of Comparative Example 3.

In the case of constant current control, the current value is controlled to about 1 mA, although it fluctuates to some extent at the beginning of energization. In this way, by stabilizing the current value that is directly involved in the acceleration of corrosion, the acceleration reproducibility of corrosion is improved. That is, the reliability of the corrosion resistance test is increased.

On the other hand, in the case of the constant voltage control, the current value greatly fluctuates, which is disadvantageous in terms of accelerated reproducibility of corrosion. During the period when the fluctuation of the current value from the start of energization to around 7000 seconds is large, it corresponds to the period when water permeates the electrodeposition coating film 4, and the permeation of water into the coating film does not proceed steadily, so the current value is large. It is recognized as fluctuating. Even after that, the current value fluctuated within the range of 0.5 mA to 1.5 mA, which is considered to be due to the fluctuation of the resistance value due to the deterioration of the chemical conversion film and rusting. In addition, in the corrosion resistance test method according to the present embodiment, since the holding step is provided before the energization step, the fluctuation of the current value from the start of energization to around 7000 seconds can be suppressed. From the current plot (current waveform) under constant voltage control, it is considered possible to grasp the progress state of corrosion or the degree of corrosion in the course of progress of corrosion.

<Effect>
As described above, when the corrosion resistance test apparatus according to the present embodiment is used, it is possible to perform a highly reliable corrosion resistance test in a shorter period compared to the actual corrosion test as shown in Test Example 1. In particular, by placing the container 30 having the plurality of through-holes 11 that accommodates the water-containing electrolyte material 6 on the electrodeposition coating film 4, the water-containing electrolyte material 6 is brought into contact with each of the plurality of measurement portions 4A. Can be placed. Then, since the through hole 11 functions as the water-containing electrolyte material holding portion, a highly reliable corrosion resistance test can be performed with a simpler configuration. Further, since the plurality of through holes 11 are provided in one container, it becomes easy to dispose the hydrous electrolyte material 6 so as to come into contact with the predetermined measurement portion 4A, and at the same time in disposing the hydrous electrolyte material 6. Positional deviation is unlikely to occur and the reliability of the corrosion resistance test can be improved.

In addition, preferably, when the artificial scratch 5 is provided on the measurement portion 4A and the simulated mud containing the clay mineral is adopted as the water-containing electrolyte material 6, water quickly permeates the coating film and the corrosion resistance test described above is performed quickly. In addition, it can be performed stably. Further, a holding step is provided before the energization step, and in the holding step and the energization step, the water-containing electrolyte material 6 and the coating metal material 1 are heated to a predetermined temperature and held, so that the electrodeposition coating film 4 The migration of ions and the penetration of water can be promoted in advance. Then, the corrosion progress rate can be evaluated in a shorter time and with high accuracy.

The corrosion resistance test apparatus according to the present embodiment can be suitably used, for example, in a manufacturing process of an automobile member or the like, in a case where a part is taken out from the manufacturing line for each coating process and the quality of the coating film is confirmed.

(Second embodiment)
Hereinafter, other embodiments according to the present disclosure will be described in detail. In the description of these embodiments, the same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

A cover 38 shown in FIG. 13 may be provided so as to cover the container 30 and the coated metal material 1 of FIG. The cover 38 includes, for example, a cover body 381, a cutout portion 382 provided on a side surface of the cover body 381, and a grip portion 383 provided on an upper portion of the cover body 381. While holding the grip portion 383 and taking out the wiring of the external circuit 7 and the temperature controller 36 from the cutout portion 382, the cover 38 is arranged so as to cover the entire container 30 and the coated metal material 1 by the cover body 381. With this configuration, the temperature of the hydrous electrolyte material 6 and the coating metal material 1 can be easily adjusted and the temperature can be kept constant, so that the reliability of the corrosion resistance test can be improved.

(Other embodiments)
There may be three or more measurement portions 4A. Further, three or more through holes 11 of the container 30 may be provided. Further, the measurement portion 4A may not be provided with the artificial scratch 5. When three or more measurement portions 4A are provided, the artificial scratches 5 may or may not be provided on all or some of the measurement portions 4A.

The outer shape of the container 30 is not limited to that of the first embodiment, and may be a member having another shape such as a rectangular shape in plan view.

The coated metal material 1 does not have to have a plate shape, and may have a block shape, a rod shape, a spherical shape, or the like, and the measurement portion 4A may be located on a curved surface or a corner portion. In this case, the shapes of the container 30 and the through hole 11, the shape of the electrode 12, and the like can be appropriately changed according to the shape of the measurement portion 4A.

The container 30 may not have the sheet-shaped sealing material as the bottom 32. In this case, for example, a rubber mat having a hole for exposing the measurement portion 4A or a sheet made of silicone resin is arranged on the electrodeposition coating film 4 of the coated metal material 1, and the container 30 is placed thereon. Good.

The magnet 33 may not be provided, and when provided, it is not limited to the ring-shaped magnet, and for example, a plurality of block-shaped, disc-shaped, or spherical magnets may be provided around the through hole 11. A magnet sheet or the like may be provided as part of the bottom portion 32.

Further, instead of providing the rubber heater 34 and the hot plate 35, the entire apparatus may be heated and temperature adjusted in the furnace.

In the above embodiment, the electrodeposition coating film 4 was provided as the surface treatment film, but the coated metal material 1 may be provided with a multilayer film having two or more layers as the surface treatment film. Specifically, for example, in addition to the electrodeposition coating film 4, a structure in which an intermediate coating film is provided on the surface of the electrodeposition coating film 4, or a configuration in which an overcoating film or the like is further provided on the intermediate coating film It can be a multilayer film.

The intermediate coating film has the roles of ensuring the finish and chipping resistance of the coated metal material 1 and improving the adhesion between the electrodeposition coating film 4 and the top coating film. Further, the top coating film ensures the color, finish and weather resistance of the coated metal material 1. These coating films are, for example, paints composed of a base resin such as polyester resin, acrylic resin or alkyd resin, and a crosslinking agent such as melamine resin, urea resin or polyisocyanate compound (including block). Can be formed by.

In the above embodiment, the electrode 12 is a perforated electrode having the hole 12a, but it may be an electrode having no hole 12a. Further, the electrode shape is not particularly limited, and an electrode having a shape generally used in electrochemical measurement can be adopted.

The present disclosure is extremely useful because it can provide a corrosion resistance test apparatus that can improve the reliability of the corrosion resistance test with a simple configuration.

1 Coated metal material 2 Steel plate (metal base material)
3 Chemical conversion film (metal base material)
4 Electrodeposition coating film (surface treatment film)
4A Measurement Part 5 Artificial Wound 6 Hydrous Electrolyte Material 7 External Circuit 8 Energizing Means 11 Through Hole (Hydrohydrate Electrolyte Material Retaining Section)
11A Opening 12 Electrode 12a Hole 30 Container 31 Main Body 32 Bottom 32A Bottom 33 Magnet 34 Rubber Heater (First Heating Element)
35 hot plate (second heating element)
36 Temperature Controller 38 Cover 100 Corrosion Resistance Testing Device 301 Extension Part 302 Pedestal Part 304 Groove Part 381 Cover Main Body 382 Notch Part 383 Gripping Part

Claims (13)

A corrosion resistance test device for a coated metal material, comprising a metal base material and a surface treatment film,
A container, which is placed on the surface-treated film and has a plurality of water-containing electrolyte material holding portions that open at the bottom surface in contact with the surface-treated film,
Accommodated in each of the water-containing electrolyte material holding portion of the container, a water-containing electrolyte material in contact with each of a plurality of separated measurement portion of the surface treatment film,
A plurality of electrodes contacting the water-containing electrolyte material contained in each of the water-containing electrolyte material holding portion,
An external circuit connecting between the plurality of electrodes,
An apparatus for testing corrosion resistance of a coated metal material, comprising: an energizing means for energizing the metal base material via the electrode and the external circuit. In claim 1,
The bottom of the container is flat,
Each of the above-mentioned water-containing electrolyte material holding portions is provided with an opening provided on the bottom surface thereof, and comprises a through hole penetrating the container in a direction perpendicular to the bottom surface. In claim 2,
The metal base material is a steel plate,
The said container is equipped with the magnet arrange|positioned at the said bottom face side and each opening vicinity of each said through-hole, The corrosion resistance test apparatus of the coating metal material characterized by the above-mentioned. In any one of Claim 1 thru|or Claim 3,
A first heating element arranged on the outer peripheral portion of the container so as to cover the outer periphery of the water-containing electrolyte material holding portion,
A corrosion resistance test apparatus for a coated metal material, comprising: a temperature controller connected to the first heating element to control the temperature of the first heating element. In claim 4,
A second heating element disposed on a side of the coated metal material opposite to a side on which the container is disposed,
The temperature resistance of the said 1st heating element and the said 2nd heating element is controlled to 30 to 100 degreeC by the said temperature controller, The corrosion resistance test apparatus of the coating metal material characterized by the above-mentioned. In any one of Claim 1 thru|or 5,
The container is
A bottom made of a silicone resin that forms the bottom of the container,
A corrosion resistance test apparatus for a coated metal material, comprising: a main body made of an insulating resin material and extending on the side opposite to the bottom surface of the bottom portion. In any one of Claim 1 thru|or Claim 6,
Each of the measurement portions includes an artificial scratch that penetrates the surface-treated film to reach the metal substrate,
At least one of the artificial scratches serves as an anode site and the other at least one serves as a cathode site by the energizing means, so that the metal base material is energized so that corrosion of the coated metal material proceeds. Corrosion resistance tester for coated metal materials. In claim 7,
The distance between the plurality of artificial scratches is 2 cm or more. In claim 7 or claim 8,
A diameter of the artificial scratch on the cathode site is 0.1 mm or more and 5 mm or less, and a corrosion resistance test device for a coated metal material. In any one of Claim 1 thru|or Claim 9,
The corrosion resistance test apparatus for coated metal material, wherein the current supplied by the current supplying means is a current value of 10 μA or more and 10 mA or less. In any one of Claim 1 thru|or Claim 10,
The above-mentioned hydrous electrolyte material is a mud-like material containing water, a supporting electrolyte and a clay mineral, and a corrosion resistance test device for a coated metal material. In claim 11,
The above-mentioned clay mineral is a layered silicate mineral or zeolite, and a corrosion resistance test device for coated metal materials. In any one of Claim 1 thru|or Claim 12,
The said surface treatment film is a resin coating film, The corrosion resistance testing apparatus of the coating metal material characterized by the above-mentioned.